For analyzing a sample using a mass spectrometer, introduction of an ionized sample is basically necessary. Thus, the ion source is disposed in a stage prior to the mass spectrometer. The ion source may be classified into various types according to their different ionization methods. For example, the ion source is classified into EI method, CI method, ESI method, and ACPI method. Regardless of which ion source is used, ion generation or the measurement state of the mass spectrometer may become unstable. In that case, adjustment of the ion source or the mass spectrometer is necessary.
In the following, a case in which ion generation or the measurement state of the mass spectrometer become unstable will be described with reference to a quadrupole ion trap mass spectrometer as an example. In this mass spectrometer, ions introduced from the ion source to an ion trap are trapped by an Rf electric field for only a certain time, and concentrated ions are successively ejected from the ion trap in accordance with their mass to charge ratio (m/z), and a change in the intensity value is detected by a detector so as to analyze the mass of the sample.
It is known that there is a limit to the amount of ion that can be trapped in the ion trap. It is also known that, even in a transitional status before the trapping-enabled limit amount is reached, a phenomenon referred to as a space charge effect (a phenomenon in which the apparent mass is displaced) occurs when the amount of ion exceeds a certain level. This phenomenon is caused by a displacement in the ion's pseudopotential due to the charge of the ion, affecting the mass analysis principle of the ion trap.
The mass spectrometer is normally used in a laboratory where the environment conditions such as temperature and humidity are constantly maintained. This is because if the environment conditions are changed, the measurement accuracy may be influenced by variation in the control circuit operation or a change in the physical length of the device, for example. Thus, generally, in order to maintain measurement accuracy, an operation such as calibration or sensitivity confirmation is performed before measurement. As needed, adjustments, washing, device parameter modifications and the like may also be performed. Measurement of the concentration of the sample as the object of measurement and preliminary measurement, namely a sample preprocessing, concentration adjustment, measurement condition optimization and the like may also be performed. Such preparation work is normally conducted by a person having knowledge of chemical experimentation or mass analysis, or under the supervision of such personnel.